Beam clamp with adjustable jaw



N0V 18, 1952 W. H. FERGUSON ETAL 2,618,303

BEAM CLAMP WITH ADJUSTABLE JAW 2 SHEETS-SHEET l Original Filed June 14, 1946 NOV 18, 1952 w. H. FERGUSON ETAL 2,618,303

BEAM CLAMP WITH ADJUSTABLE JAw Original Filed June 14, 1946 2 SHEETS-SHEET 2 Patented Nov. 18, 1952 BEAM CLAMP WITH ADJUSTABLE JAW William H. Ferguson, Malden, Harry C. Ferguson, Melrose, and John W. Geddes, Boston, Mass., assignors to H. K. Porter, Inc., Everett. Mass., a corporation of Massachusetts Original application June 14, 1945, ,Serial No.

Divided and this application April 3, 19,46, Serial No. 659,294

3 Claims. 1

This invention relates Ito clamps and the bject is to provide an improved form of clamp which may be quickly adjusted to the work, will have superior holding qualities when set up but which may be easily released. The clamp nds a particular iield of application in connection with a machine for positioning automobile parts for reforming operations as described in our applical tion Serial No. 599,380, led June 14, 1945 and later abandoned, of Which the present application is a division, that appliance being of the same general type as that disclosed in the patent to Ferguson 2,275,894.

Our invention will be well understood by reference to the following -description of an illustrative embodiment thereof shown by way of example in the accompanying drawings, wherein:

Fig. 1 is a side elevation of a clamp, partly broken away, and illustrated in connection with supporting means therefor shown partly in section;

Figs. 2 and 3 are sections on the correspondingly numbered lines of Fig. 1;

Fig. 4 is an enlargement of a portion of Fig. l at the point where the adjustable jaw-carrying arm is attached to the bar;

Figs. 5 and 6 are sections on the correspondingly numbered lines of Fig. 4; and

Fig. '7 is a perspective view of the Wedge element which forms a part of the clamping device.

Referring to the drawings, the clamp is designated generally by the numeral .and may comprise a clamp body 68 of generally J-shaped or L-shaped form and conveniently'having the general section of an I beam as shown, the end of the shorter leg of the J carrying a jaw l0, herein illustrated as of relatively large area and padded. A cooperating jaw 18, herein similarly of large area and likewise padded, cooperates with the lower jaw to receive the work between the two jaw surfaces and is organized on an arm 80 slidably received on the longer arm of the J-shaped member B8, being swivelled on the end of a screw 82 traversing the arm 80, which screw may be turned by means of the handle 85. In use the arm 80 is run in along the upright of the member 68 until the jaws engage the work. and the screw s2 is set up to provide the clamping pressure, the arm 8D then being held in its adjusted position. A clamp having the general construction described in this paragraph is not essentially new and our invention more particularly relates to improvements facilitating the adjustment and justed position in a secure manner (Cl. 14A-303) As seen in Fig. 6, the form of the member 68 is such that the arm 8,0 may be withdrawn completely past the upper end of the same, this facilitating the introduction of the work to the clamp and its withdrawal therefrom, more particularly in connection with a mechanism as disclosed in the parent application.

We shall now describe the detailed construction of the arm Si) herein illustrated. This arm has an opening 86 therethrough through which the bar formed by the long leg of the Jshaped clamp body 68 extends so that the arm slides freely along the latter. The t is somewhat loose to permit ready application and removal of the arm over the free end of the bar B8 and grip is provided by a sliding wedge 88 which forms in effect the surface of the arm which engages the outer or back flange of the bar 68 and which is normally pressed to gripping position by a spring Sill.v The particular form and arrangement of the wedge herein illustrated will be more fully described later. Preferably the face of the wedge and the opposed face of the bar, while of the same contour as is illustrated in Fig. 7, are substantially smooth. That is, the grip is a frictional one.

To provide adequate grip of the arm on the bar 68, while providing adequate depth of the arm for purposes of strength, the inner surface of opening 86 at the side opposite the wedge and presented to the inner or front side of bar 68 is formed to provide a fulcrum point for the arm at 92, opposite the wedge and between the upper and lower sides of the arm, viewing Fig. 4. This may be formed by cutting away the upper portion of the surface at a slight angle as best indicated by the extended line 94 in Fig. 4. Otherwise described, the left-hand inner surface of the opening 86, viewing Fig. 4, comprises two faces defining between them at an angle (supplementaryl to the angle `indicated at 94) which is somewhat less than a straight angle and has its vertex presented to the bar 68. When operation of the screw 82 tends to lift the left-hand end of the arm, viewing Figs. 1 and 4, the arm tends to roclf:l clockwise on rthe fulcrum at 92 and pressure is exerted on the wedge 88 through a short lever' arm about that point and at a favorable angle to insure eiiective locking pressure thereon.l Because of the comparatively rough construction of the parts, wheny clamping pressure has been exerted `the receding face above the point 92 will engage the opposed edge of the bar.

When `the screw 82 is loosened, the wedge 8B may be pressed back against the force of Vthe spring 90 and the arm 80 readily slipped from the end of bar 68. To retain the wedge as a unit with the arm we have herein shown the same as housed within a recess 96 at one side of the opening 86, which recess is closed at the top by the overhanging wall 98. The sides of the recess have ribs |00, best seen in Figs. and 6, the further one behind wedge 88 being shown in dotted lines in Fig. 4, which ribs dene open-topped pockets facing upwardly toward the under surface of the wall 98. The base of the wedge 8B, as best seen in Figs. 5 and 7, is provided with projections |02 extending laterally outwardly. The wedge may be inserted from the lower side of opening 86 and these projections |02 passed in between the upper ends of the ribs |00 and the lower surface of wall 98 and dropped into the pockets. The wedge here shown has a tail |04 projecting outwardly between which and the back of the arm 80 the compression spring 90 is interposed, the spring preferably being partly received in a well |06 formed in the back of the arm opposite the tail. The spring conveniently is of double volute form and seats on pin-like projections |03 on the tail and on the bottom wall of well |06.

When arm 80 is in position on the bar 68, the wedge cannot move to the left in Fig. 4 except for such slight movement as is incident to its gripping action. When the arm is separated from the bar, normal compression of the spring 90 will not raise the projections |02 clear of the ribs |00. Moreover, the spring 90 is disposed at such an angle that its reaction tends to force the point of the wedge toward the left and resist escape of the projections at its base to the left over the ends of the ribs.

The wedge assembled as described cannot become displaced but is held adjacent the outer side of the opening 86 through the arm 80 and can be moved freely upwardly against the spring or lbe pressed downwardly by the spring as required.

We have herein shown the well |06 as formed in an extension or projection I0 from the back of the arm, this extension and the tail |04 of the wedge being adapted to be encircled by the thumb and forefinger of the hand when it is desired to press back the wedge, these parts also forming a grip for this hand when the arm is to be lifted to free it from the bar.

In the drawing the clamp 36 is shown as organized on a base 54 which has at one side a seat for positioning on a supporting structure such as the beam 32 illustrated in Figs. 1 and 2, to be held thereagainst in the desired position of longitudinal adjustment along the beam by the clamping bolt 40. The base 60 has at its other side upstanding spaced cheeks 66, betweenwhich is slida-bly received the clamp body 68 to be gripped between the cheeks at any desired point along its length. In the preferred construction herein shown (see Figs. 1 and 2) there project inwardly from one of the cheeks three triangularly arranged pins l2 which engage the web of the I between the flanges thereof and provide a guide for the body 68 in the sliding adjustment between the cheeks, and a set screw 'M with an operating handle 'I5 is threaded into the other cheek and opposes the web at a point within the triangle, as will be clear from Figs. 2 and 1, the point of engagement of the screw being indicated by the numeral 16.

It will be apparent that the invention may be embodied in other specic forms without departing from the spirit or essential attributes thereof, and the present embodiment should therefore be considered in all respects as illustrative and not restrictive, as is in fact clear in several matters from the description itself. Reference is to be had to the appended claims to indicate those principles of the invention exemplified by the particular embodiment described and which it is desired to secure by Letters Patent.

We claim:

1. A clamp structure comprising a bar having a laterally projecting jaw, a removable arm having a cooperating jaw and provided with an opening which may be threaded over the end of the bar remote from the first jaw and slide along the length of the bar, the wall of the opening having a recess opposing the side of the bar the wall of the recess remote from the bar being inclined relatively thereto, a cooperating wedge in the recess presented to the side of the bar for contact therewith, the wedge having laterally projecting lugs adjacent its base, the sides of the recess having pockets with closed bottoms and open tops through which the lugs may be introduced into the pockets and a spring tending to bottom the lugs in the pockets and to project the wedge along the inclined wall of the recessl lengthwise of the bar to cause it to bind on the bar the depth of the pockets providing for retractive movement of the wedge against the spring to release the bar without displacement of the lugs from the pockets.

2. A clamp structure comprising a bar having a laterally projecting jaw, a removable arm having a cooperating jaw and provided with an opening which may be threaded over the end of the bar remote from the first jaw and slid along the length of the bar, the wall of the opening having a recess opposed to the side of the bar and closed at the top the wall of the recess remote from the bar being inclined relatively thereto, a cooperating wedge in the recess presented to the side of the bar for contact therewith, the wedge having laterally projecting lugs adjacent its base, the sides of the recess having pockets with closed bottoms and open tops facing the top of the recess in spaced relation thereto, through which tops the lugs may be introduced into the pockets and a spring tending to bottom the lugs in the pockets and to project the wedge along the inclined wall of the recess lengthwise of the bar to cause it to bind on the bar the depth of the pockets providing for retractive movement of the wedge against the spring to release the bar without displacement of the lugs from the pockets.

3. A clamp structure comprising a bar having a laterally projecting jaw, a removable arm having a cooperating jaw and provided with an opening which may be threaded over the end of the bar remote from the first jaw and slid along the length of the bar, the wall of the opening having a recess opposed to the side of the bar and closed at the top the wall of the recess remote from the bar being inclined relatively thereto, a cooperating wedge in the recess presented to the side of the bar for contact therewith, a wall of the recess being formed to provide a pocket having an open top separated by a space from the top of the recess the Wedge having a projecting portion to pass through the space and enter the pocket through the open top to retain the wedge in the recess and a spring tending to press the projection downwardly into the pocket and to project the Wedge lengthwise of the bar to cause it to bind on the bar, the depth of the pocket provided for retractve movement of the wedge Number against the spring to free the bar without ds- 792,213 placement of the projection from the pocket. 893,949 WILLIAM H. FERGUSON. glg HARRY C. FERGUSON. 5 1 0801536 -l-.v J JOHN W. GEDDES. llglgoo REFERENCES CITED g] The following references are of record in the 10 2061'217 111e of this patent: 2290,002

UNITED STATES PATENTS Number Name Date 663,283 Lee Dec. 4, 1900 Number 678,805 Weyand July 16, 1901 15 20,842 681,591 Tillman Aug. 27, 1901 101,716

Name Date House June 13, 1905 Taylor July 21, 1908 Peterson Nov. 3, 1908 Paquette Feb. 2, 1909 Case Dec. 9, 1913 Reeder Oct. 28, 1919 Rose et al. Feb. 20, 1934 Snavely Aug. 18, 1936 Watcher Nov. 17, 1936 McKay May 6, 1947 FOREIGN PATENTS Country Date Great Britain Dec. 20, 1890 Sweden June 3, 1941 

